sleep cycles
Nightly rest stages
Sleep cycles are the recurring patterns of sleep stages the brain moves through during a night's rest, typically lasting about 90 minutes each.
A full night includes several cycles, progressing from light sleep through deep sleep to REM sleep, then repeating.
I woke up groggy because my alarm interrupted a sleep cycle.
Understanding sleep cycles helps explain why some wake times feel more refreshing than others.
- brain wavesElectrical patterns from neurons
- insomniaPersistent inability to rest
- circadian rhythmBuilt-in sleep-wake cycle
- body clockInternal time-keeping system
- melatoninCircadian rhythm regulator
adenosine · bedtime routines · thalamus · acetylcholine · light exposure · homeostasis · chronotype · early bird · napping · hitting snooze · snoring · brainstem · waking · temperature regulation · bedtime · tossing · counting sheep · restless
- biorhythmscircadian rhythm, circadian rhythms, circadian clock, biological clocks, biological clock
- aerospace medicinebioastronautics, microgravity, zero gravity, pressure suit, space suit
- sleepsleeping, nap, doze, slumber, naps
- cyclescircle of life, cycles, period, rhythms, oscillations
- physiologymetabolism, circulation, respiration, homeostasis, digestion
- automatic processesbreathing, heartbeat, reflex, digestion, blinking